Summary
17 Cygni is the Flamsteed designation for a multiple star system[3] in the northern constellation of Cygnus. It has an apparent visual magnitude of 5.00,[2] so, according to the Bortle scale, it is visible from suburban skies at night. Measurements of the annual parallax find a shift of 0.0477″,[1] which is equivalent to a distance of around 68.5 ly (21.0 pc) from the Sun. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.451″/year.[11]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 46m 25.600s[1] |
| Declination | +33° 43′ 39.35″[1] |
| Apparent magnitude (V) | 5.00[2] + 8.56[3] |
| Characteristics | |
| Spectral type | F7 V[2] + K6 V + K3 V + K3 V[3] + M0.4[4] |
| B−V color index | 0.46[2] |
| Astrometry | |
| Radial velocity (Rv) | +4.1[5] km/s |
| Proper motion (μ) | RA: +22.745 mas/yr[1] Dec.: –448.311 mas/yr[1] |
| Parallax (π) | 47.6516 ± 0.0675 mas[1] |
| Distance | 68.45 ± 0.10 ly (20.99 ± 0.03 pc) |
| Absolute magnitude (MV) | 3.40[2] |
| Details | |
| 17 Cyg A | |
| Mass | 1.24[6] M☉ |
| Radius | 1.538[7] R☉ |
| Luminosity | 3.66[8] L☉ |
| Surface gravity (log g) | 4.262[8] cgs |
| Temperature | 6,455[8] K |
| Metallicity [Fe/H] | 0.027[8] dex |
| Rotational velocity (v sin i) | 9[2] km/s |
| Age | 2.8[9] Gyr |
| 17 Cyg B | |
| Mass | 0.65 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
This system consists of two visual binary systems that were discovered by John Herschel in the 1820s. Components A and B form a bright, wide pair with an angular separation of 26.0 arcsecond and an estimated orbital period of ~6,200 years. The faint, close system consists of components F and G with a separation of 2.6 arcsecond and a period of 238 years. The two binaries form a hierarchical system with a separation of about 800 arcseconds and orbital period of 3.7 million years or more.[3] At an angular separation of 791.40 arcseconds is a proper motion companion with a classification of M0.4, indicating this is a red dwarf star. At the estimated distance of the pair, this is equal to a projected separation of 16,320 AU.[4] Although the CCDM lists four other companions, these are not associated with the system.[12]
The stellar classification of the primary star, component A, is F7 V,[2] which means it is a main sequence star like the Sun. The star has 1.24[6] times the mass of the Sun and 1.54[7] times the Sun's radius. It is some 2.8[9] billion years old and shines with 3.66[8] times the Sun's luminosity. The effective temperature of the stellar atmosphere is 6,455[8] K, giving it the yellow-white hued glow of an F-type star.[13]
References edit
- ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b c d e f g Takeda, Yoichi; et al. (February 2005), "High-Dispersion Spectra Collection of Nearby F--K Stars at Okayama Astrophysical Observatory: A Basis for Spectroscopic Abundance Standards", Publications of the Astronomical Society of Japan, 57 (1): 13–25, Bibcode:2005PASJ...57...13T, doi:10.1093/pasj/57.1.13.
- ^ a b c d Romanenko, L. G. (March 2017), "A dynamical study of the multiple system 17 Cygni ABFG", Astronomy Reports, 61 (3): 206–220, Bibcode:2017ARep...61..206R, doi:10.1134/S1063772917020056, S2CID 255199959.
- ^ a b Dhital, Saurav; et al. (June 2010), "Sloan Low-mass Wide Pairs of Kinematically Equivalent Stars (SLoWPoKES): A Catalog of Very Wide, Low-mass Pairs", The Astronomical Journal, 139 (6): 2566–2586, arXiv:1004.2755, Bibcode:2010AJ....139.2566D, doi:10.1088/0004-6256/139/6/2566, S2CID 661494.
- ^ Nordström, B.; et al. (May 2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14,000 F and G dwarfs", Astronomy and Astrophysics, 418 (3): 989–1019, arXiv:astro-ph/0405198, Bibcode:2004A&A...418..989N, doi:10.1051/0004-6361:20035959, S2CID 11027621.
- ^ a b Halbwachs, J. -L; et al. (2018), "Multiplicity among solar-type stars. IV. The CORAVEL radial velocities and the spectroscopic orbits of nearby K dwarfs", Astronomy and Astrophysics, 619: A81, arXiv:1808.04605, Bibcode:2018A&A...619A..81H, doi:10.1051/0004-6361/201833377, S2CID 119437322.
- ^ a b Schofield, Mathew; et al. (2019), "The Asteroseismic Target List for Solar-like Oscillators Observed in 2 minute Cadence with the Transiting Exoplanet Survey Satellite", The Astrophysical Journal Supplement Series, 241 (1): 12, arXiv:1901.10148, Bibcode:2019ApJS..241...12S, doi:10.3847/1538-4365/ab04f5, S2CID 119481586.
- ^ a b c d e f Takeda, Yoichi (April 2007), "Fundamental Parameters and Elemental Abundances of 160 F-G-K Stars Based on OAO Spectrum Database", Publications of the Astronomical Society of Japan, 59 (2): 335–356, Bibcode:2007PASJ...59..335T, doi:10.1093/pasj/59.2.335.
- ^ a b Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511.
- ^ "* 17 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2013-10-26.
- ^ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal, 129 (3): 1483–1522, arXiv:astro-ph/0412070, Bibcode:2005AJ....129.1483L, doi:10.1086/427854, S2CID 2603568.
- ^ Phillips, N. M.; et al. (April 2010), "Target selection for the SUNS and DEBRIS surveys for debris discs in the solar neighbourhood", Monthly Notices of the Royal Astronomical Society, 403 (3): 1089–1101, arXiv:0911.3426, Bibcode:2010MNRAS.403.1089P, doi:10.1111/j.1365-2966.2009.15641.x, S2CID 119262858. See the note for F094.
- ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on March 18, 2012, retrieved 2012-01-16.